There are at least two alternative interpretations.
1) Quirrel said this while he was roleplaying as the defense professor. Perhaps the role he came up with happened to be constructed so that Harry's actions made him happy. But that doesn't mean that it made Riddle happy (insofar as the "true" identity of Riddle exists). Heck, we don't even know that Harry is dealing with Riddle in chapter 108, or yet another identity that Riddle selected for the occasion. (He "changes names as you or I change clothes.")
2) Even if Quirrel/Riddle was not roleplaying, this could have been a calculated statement made in order to gain Harry's trust and admiration. There seems to have been a lot of that going on in Harry's interactions with Quirrel.
New long chapter! Since I expect its discussion to generate more than 160 comments (which would push the previous thread over the 500 comment limit) before the next chapter is posted, here is a new thread.
This is a new thread to discuss Eliezer Yudkowsky’s Harry Potter and the Methods of Rationality and anything related to it. This thread is intended for discussing chapter 108
(and chapter 109, once it comes out on Monday).EDIT: There have now been two separate calls for having one thread per chapter, along with a poll in this thread. If the poll in this thread indicates a majority preference for one thread per chapter by Monday, I will edit this post to make it for chapter 108 only. In that case a new thread for chapter 109 should be posted by whoever gets a chance and wants to after the chapter is released.
EDIT 2: The poll indicates a large majority (currently 78%) in favor of one thread per chapter. This post has been edited accordingly.
There is a site dedicated to the story at hpmor.com, which is now the place to go to find the authors notes and all sorts of other goodies. AdeleneDawner has kept an archive of Author’s Notes. (This goes up to the notes for chapter 76, and is now not updating. The authors notes from chapter 77 onwards are on hpmor.com.)
Spoiler Warning: this thread is full of spoilers. With few exceptions, spoilers for MOR and canon are fair game to post, without warning or rot13. More specifically: